Used primarily as an intermediate in the production of dyes, pigments, and other organic compounds. It acts as a catalyst in various chemical reactions, particularly in esterification and polymerization processes. In the pharmaceutical industry, it serves as a raw material for synthesizing active pharmaceutical ingredients (APIs). It is also employed in the manufacture of detergents and surfactants due to its sulfonic acid group, which enhances cleaning efficiency. Additionally, it finds use in water treatment processes as a dispersant and scale inhibitor.